Microbial Removal of Petroleum Hydrocarbons from Contaminated Soil under Arsenic Stress.

The contamination of soils with petroleum and its derivatives is a longstanding, widespread, and worsening environmental issue. However, efforts to remediate petroleum hydrocarbon-polluted soils often neglect or overlook the interference of heavy metals that often co-contaminate these soils and occur in petroleum itself. Here, we identified Acinetobacter baumannii strain JYZ-03 according to its Gram staining, oxidase reaction, biochemical tests, and FAME and 16S rDNA gene sequence analyses and determined that it has the ability to degrade petroleum hydrocarbons. It was isolated from soil contaminated by both heavy metals and petroleum hydrocarbons. Strain JYZ-03 utilized diesel oil, long-chain n-alkanes, branched alkanes, and polycyclic aromatic hydrocarbons (PAHs) as its sole carbon sources. It degraded 93.29% of the diesel oil burden in 7 days. It also had a high tolerance to heavy metal stress caused by arsenic (As). Its petroleum hydrocarbon degradation efficiency remained constant over the 0-300 mg/L As(V) range. Its optimal growth conditions were pH 7.0 and 25-30 °C, respectively, and its growth was not inhibited even by 3.0% (w/v) NaCl. Strain JYZ-03 effectively bioremediates petroleum hydrocarbon-contaminated soil in the presence of As stress. Therefore, strain JYZ-03 may be of high value in petroleum- and heavy-metal-contaminated site bioremediation.

Effect of Pyrolysis Temperature on the Sorption of Cd(II) and Se(IV) by Rice Husk Biochar.

This study investigated the removal of metal cations (Cd(II)) and metalloid anions (Se(IV)) from their aqueous solution by using agricultural waste (rice husk biochar). Rice husk biochar samples were prepared under 300, 500, and 700 °C pyrolysis conditions and their physicochemical properties were characterized. Aqueous Cd(II) and Se(IV) sorption kinetics and isotherms of rice husk biochar were studied. The results showed that the yield of rice husk biochar decreased from 41.6% to 33.3%, the pH increased from 7.5 to 9.9, and the surface area increased from 64.8 m2/g to 330.0 m2/g as the pyrolysis temperature increased from 300 °C to 700 °C. Under the experimental conditions, at increasing preparation temperatures of rice husk biochar, the sorption performance of Cd(II) and Se(IV) was enhanced. The sorption capability and sorption rate were considerably higher and faster for Cd(II) ions than for Se(IV) ions. Cd(II) sorption was found to reach equilibrium faster, within 150 min, while Se(IV) sorption was slower and reached equilibrium within 750 min. The maximum sorption capacities of cadmium and selenium by rice husk biochar were 67.7 mg/g and 0.024 mg/g, respectively, according to Langmuir model fitting.

[Composition Characteristics and Construction Mechanism of Microbial Community on Microplastic Surface in Typical Redox Environments].

Microplastics are widely distributed in the biogeochemical cycle driven by microbes. Their surface is enriched with unique microbial communities, called plastispheres. Various redox environments that exist widely in the natural environment can affect the microbial composition in the plastisphere and the fate of the microplastics. To explore the microbial community composition and construction mechanism on the surface of microplastics in typical redox environments, three microplastics, PHA (polyhydroxyalkanoates), PLA (polylactic acid), and PVC (polyvinyl chloride), were placed in five specific redox environments:aerobic, nitrate reduction, iron oxide reduction, sulfate reduction, and methane production. The culture experiment simulated the microcosm, which was inoculum by sludge. The results showed that microplastic factors affected 18.94% and 46.67% of the microbial communities on the plastisphere in taxonomy and phylogeny, respectively. Redox factors affected 31.04% and 90.00% of the microbial communities on the plastisphere in taxonomy and phylogeny, respectively. Compared with that in sludge, the microbial community richness and diversity were reduced on the three microplastics. The most apparent reduction was found on the plastisphere of more degradable PHA. At the same time, microbial communities on the refractory PLA and PVC surfaces remained similar. Anaerocolumna (26.44%) was the dominant genus on the surface of PHA microplastics, whereas microbes related to the redox reaction were less enriched. Clostridium_sensu_stricto_7 (15.49% and 11.87%) was the dominant strain on PLA and PVC microplastics, and the microbes related to the redox reaction were significantly enriched. Thus, characteristic microbes involved in the redox reaction will be enriched in the surface of refractory microplastics, and microplastics may affect the rate of biogeochemical cycling.

[Umbilical ring acupoints and its clinical application in Zhuang medicine].

The theoretical basis, location, belonging of zang-fu, treatment function and indications, applying principle and manipulation of Umbilical Ring acupoints in Zhuang medicine are explained in this paper. According to Zhuang medicine, umbilicus is an epitome of the body and all the zang-fu and organs in the body have corresponding epitomes like a fetus in front-standing position. The umbilicus is not only a micro-diagnosis system, but also a window for illness treatment that could be divided into superficial, middle and deep layer to respectively communicate different zang-fu and organs. The umbilical inner ring and outer ring are collectively called Umbilical Ring acupoints, they could dredge paths, regulate the balance of qi and blood to regulate qi, expel poison, tonify deficiency and remove stasis to treat many types of diseases in the whole body.